Presentation and characterisation of the ALBA micro8 system for targeted hyperthermia in small animal research

Preclinical therapeutic hyperthermia cancer research provides essential insight into biological and physiological effects, therapeutic impacts, and treatment-strategy optimisation. As hyperthermia triggers both local and systemic effects, orthotopic tumour models are required for translational research. Preclinical hyperthermia devices capable of adequately heating orthotopic tumours were previously unavailable. To address this, a phased-array electromagnetic heating system was developed with eight 1.66 GHz waveguide antennas. This study evaluates its ability to generate and control a heating focus in phantoms, and examines its correlation with numerical predictions. Focus size and power-steering capabilities were assessed by E-field scanning for a central focus and a 10 mm shifted focus. Temperature distributions were measured in muscle-equivalent phantoms (d = 40 mm, l = 90 mm) for central and 7.5 mm shifted foci. Results were compared with simulations by Plan2Heat, a dedicated treatment planning package for hyperthermia applications. The system successfully generated confined power foci with a radial diameter of 8 mm (FWHM). The measured temperature focus was 22 × 25 mm. The simulation-predicted focus location matched measurements within 1 mm for both power and temperature. The system generates a confined, controllable, and predictable heat focus suitable for deep targets, required for effective preclinical hyperthermia research into clinically relevant biological and physiological effects. Future work should focus on validation in mice.